Conventionally, a typical method for preventing theft of electronic devices is to, for example, embed a sensor called a sensor tag on an item of merchandise or to attach it to a carton case, and install a sensor in the doorway of a store to detect and sound a buzzer when the merchandise is removed from the store without releasing the function of the sensor at a cash register. However, the effect raises a question because the sensor tag loses its effect once it is removed, and further the electronic devices are still stolen even when the buzzer goes off.
Also, the Japanese published unexamined application No. 2007-24843 discloses a digital camera provided with a voltage current detection portion and a wireless tag. The digital camera is an invention that utilizes the wireless tag, and is specifically described as follows. The voltage current detection portion detects the current value and the voltage value applied to load on each part of the digital camera, and outputs this detection value to the wireless tag. The wireless tag determines as to whether the detection value data is normal or abnormal, and the judgment information is written in a memory when the detection value is abnormal. And, when the digital camera receives a control signal from an external device, reads the abnormal detection value and transmits to the external device through an antenna of the wireless tag.
Also, the following is known as a conventional technique. First, find a Radio Frequency Identification Reader (RFID) embedded in a item of merchandise using the RFID at the time of the sale of the merchandise. When the RFID is found, read the information and transmit to a manufacturer. The manufacturer processes the information and transmits it back to the merchandise. And, the merchandise now operates.
However, any of these inventions described above are incomplete for preventing theft of electronic devices from stores. Under this circumstance, an invention which disables merchandise from use when the merchandise is stolen, demotivates thieves, and prevents this type of crime, has been desired.